“prototyping a mobile waterfilter for all urban surface waters”

“an itinerant pavilion to capture rain water”

“purilfy water "à la carte" according to the needs of its user”


wasteland rainwater city filter water quality testing encounter

tag: filter

Proper Water Pavilion (2012-13)


In an attempt to turn rain, public space enemy number one, into an ally, a temporary structure was imagined that with a funnel roof would capture rain water which would then be made fit for human consumption. It would prove the ideal catalyst for a series of discussion, debates, exchanges, the creation of artefacts and spin-off projects that carry on beyond the initial project.


After our PUM-pit experiments, we re-oriented the project. Digging up invisible water turned out to be expensive, so why not use more easily accessible, be it more polluted water, from car-wash to canal? The emphasis moved from pumping up underground water to pulling in all types of urban surface waters. As such the water point could also become a mobile purification station.

The “experts” laughed immediately at the idea that every puddle, soap water, fountain and sewage water could be filtered into drinking quality. Our reverie, however, stirred the imagination and led to rather more achievable plans concentrating solely on rainwater.

From May 2012 onwards the time was right to go outside. Different initiatives around the subject of water were grouped under the common denominator of EauPropre I ProperWater, and the machine or construction that had been tweaked over so many months had become an itinerant wooden pavilion with a funnel roof to capture rain water. A simple hand pump pushed water through a column of basic self-built filters and made it available to all those who needed it.



The Pavilion created as part of the project EauPropre | ProperWater has until now known two stages

- Stage 1, Friche Eggevoort, Summer 2012

- Stage 2, Friche Eggevoort, Summer 2013

It hosted debates, allowed to bring together networks on water and the city, to experiment during a public building site, to test DIY and more sophisticated filters and to monitor the drinking potential of filtered rain water. It was a focal point,a point for meeting and debate, harvester and purifier of rain water and a public water point.

We were able to touch on a number of subjects, ranging from technology and science, over history, politics and management to urban planning and public space.

→ 16 june to 8 july 2012 - first series of encounters - Friche Eggevoort, Brussels
→ 25 september 2012 - presentating the Pavilion during the first Salon
de l'economie Sociale d'Insertion - Les Ateliers des Tanneurs, Brussels
3 mai to 15 june 2013 - Eggevoort-Friche, Brussel
→ future installations in Brussels will be discussed collectively by the "network of water initiatives and organisations" – all propositions are welcome



The water-capture-tent or rain-harvester was built in 2012 in the course of a three-week public building site in the water garden of the Friche Eggevoort.

Additionally, we also tested a filter-system to purify rain water as natu­rally as possible, without chemicals or expensive technology. We even wondered whether or not we could bring it up to drinking water quality. With the help of the engineer Damien Smets and the chemist Antoine Pacco we built a filter column containing sand, active carbon and a UV lamp.

Between 16 June and 8 July 2012 the pavilion hosted a series of activities showcasing, questioning or testing issues relating to “water in the city”. Literacy classes, homework help, and after school activity groups explored the site, debates were held on the subject of (free access to) water and “café fil’eaus” combined drink and discussion on international solidarity and history. During info-session advice on ‘water-aware’ building and refurbishing was made available, and hands-on workshops shared skills on carpentry, design and beer brewing. Finally also rooftop-farmers, filter-experts and urban gardeners showed and shared their expertise. [see also in archive] 



In April 2013 the building on site was finalised, and the pavilion functioned fully and autonomously as a public installation for water in the city. A renewed filter system was tested and approved, and water could be purified “à la carte” according to the needs of its user. In exchange for some energy, anyone could get water in the pavilion – for as long as rain was available obviously.

From 3 May to the summer of 2013, the ProperWaterPavilion stood again at the Friche Egge­voort. We thought we owed it to the wide array of people involved in the public building site of 2012 to bring the pavilion in its full glory back to its place of origin. Syner­gies were created with urban festivals like TokTocKnock (Royal Fle­mish Theater, KVS), Matongé-Europe (Brussel-Europe liaison office), the Biodiversity Parcours (RBINS). Together with collectives like PUM and Do-it-Yourself workshops were organised and university students, cultural co-­ordinators of different local councils and transition-groups debated the sense and nonsense of capturing rainwater, harvesting, water purification and water in the city.


Choice of pumps

After the move form the PUM-pit to EauPropre I ProperWater, the pump no longer played a central part and fulfilled a simpler function, and so we searched for a less complicated pump.

We were able to test two pumps in the two versions of the pavilion. The first one was a manual semi rotary pump in cast iron, producing a good flow. However, the fact that it had rusted both inside and outside, worried us, in particular its impact on water quality. We called upon Brulabo, partner Laboratory of the project and guarantor of our filtered rain water, who told us:

“Rust is best to be avoided, for obvious technical reasons. It is harder to define health risks involved, because that depends on the metals that are corroding. Iron and copper are not toxic, nickel, chrome and lead ... are toxic. Problem is that rainwater is very corrosive, due to the total absence of calcium. As I already suggested, adding a slight bit of chalk (Ca(OH)2) in order to obtain a pH > 7,5 would undoubtedly solve the problem. “

To be on the safe side, we decided to go for a new pump, ­allowing us to add the additional requirement of being able to action the pump by foot, allowing the user to have both hands free to fill a bottle while pumping. We decided to go for a foot pump used in the naval world. Such a pump works very well when not under any pressure. But it turned out less performing when having to push water through the four membranes of the second version of the Pavilion. The narrow pores of the membrane create a resistance that translates throughout the pump which in turn blocks. This meant pavilion 2.0 distributed water at a rather weak flow rate, creating time to contemplate the preciousness of water and impo­sing a more parsimonious use.



City Mine(d) initiated the project.

The pavilion was created in collaboration with architect-engineer Kathleen Mertens. The filter cupboard was designed by architect Chris Rossaert. The joinery of the Mission Local Forest with Jacques Lechat, Juan Vandeput and the trainee workers took charge of the wooden construction. All welding was done by Danny Vandeput. ­Armando Matteo, retired construction worker with over 40 years of experience in the European neighbourhood’s large building sites, turned out to be indispensable for the structure’s stability.

Measu­ring, analysis and comparison with standards of the water quality was done by Brulabo.

Kadanja took care of signposting.

The purification of rainwater was made possible with the know-how of Josef Orszagh makes available on his eautarcie-website, the technical expertise of Gerrit of KilianWater and the pragmatism of Michel Bieswal of Compagnons Dépanneurs. Rainwater was collected by the Jardins des Arts, and Cyclo kindly allowed us to flood their workshop.


City Mine(d)

Eau Propre | Proper Water by City Mine(d)
is licensed under a Creative Commons
Attribution-NonCommercial-ShareAlike 2.0 Belgium License

Creative Commons License